The invention relates to method and apparatus for sonographic or fluoroscopic examination, biopsy, and excision; more particularly, it relates to method and apparatus for sonographic examination, biopsy, and excision within multi-chambered cavities of human and other bodies.
It is well established that the examination of body cavities is an important part of human and animal health care. Through examination of the interior of body cavities a wide variety of undesirable health conditions may be diagnosed and treated. For example, the examination of the interior of human and animal mouths for rotting and other conditions in teeth has long been practiced. A more difficult proposition, however, has been the examination of more remote or obstructed body cavities. For example, it has only recently become possible to examine the uterus of a human female without cutting the woman open and removing it. Moreover, a survey of the state of the art reveals that there is room for much improvement in the examination and treatment of body cavities, including the retrieval of biopsy samples.
An excellent example of the need for improvement in procedures and apparatus for the examination of interior body cavities is the current state of the art in uterine examination and biopsy. It has been shown that peri-and post-menopausal vaginal bleeding (PMB) is one of the most frequent reasons for postmenopausal women to seek medical attention. In the United States, such bleeding accounts for approximately 5% of all gynecologic visits; and conservative estimates predict that over the next ten years at least one million women a year within the U.S. will develop PMB. Historically, women found to suffer from PMB were subjected to hysterectomies: the complete surgical removal of the uterus. As in the case of any major surgery, however, hysterectomy has associated risks. Yet at one time hysterectomy was the most commonly performed surgical procedure in the United States.
A recent proposal as a substitute for the performance of hysterectomies has been hormone replacement therapy. Hormone replacement therapy has met with success in approximately 80% of premenopausal and approximately 50% of postmenopausal women suffering from PMB. But it has been found that hormone replacement therapy increases the risk of endometrial and breast carcinoma. Moreover, like surgical removal of suspected and (arguably) unneeded organs, hormone replacement therapy fails to treat all causes of bleeding, such as fibroid conditions, polyps, hyperplasia, and carcinoma. Thus, while hormone replacement therapy has gained widespread acceptance, it will not benefit all women.
Other proposals for the treatment of PMB and like conditions in body cavities difficult to access have included dilation and curettage procedures, and blind aspiration biopsy. Dilation and curettage comprises dilation of the cervix while the patient is under at least a local anesthesia, and the scraping of the endometrium with a spoon-like probe. Anaesthesia having been shown to be generally undesirable where not strictly necessary, however, blind aspiration biopsy techniques not generally requiring anaesthesia have been developed. But blind procedures are limited in usefulness due to low sensitivity. Blind procedures are termed xe2x80x9cblindxe2x80x9d because they involve the unguided recovery of samples taken at random from what can at most amount to a limited region of the cavity, using equipment such as suction aspiration devices or curettage instruments inserted into various body cavities without benefit or capability of visual, sonic, or other guidance. Thus the removal of samples by blind procedures gives a fair indication of the presence or absence of a malignancy with only about a 60% to 80% sensitivity. However, most recent studies have shown very low prevalences for endometrial carcinoma. Not infrequently a sample of healthy tissue is removed from the wall of a cavity within very close proximity to an undiscovered, and therefore untimely treated, malignancy.
The emerging standard of care in health care is to look at, or monitor, what is being sampled or diagnosed. Accordingly, at least one proposed alternative to the foregoing procedures has employed fiber optic spectroscopy equipment to guide the removal of tissue samples. But fiber optic equipment has been found to be, for many applicationsxe2x80x94for example, uterine examinationxe2x80x94too large to be used without patient discomfort, and its use has therefore often required the use of anaesthetics. Moreover, fiber optic equipment, due to functionally-dictated design shapes, is prone to cause injury to sensitive internal tissues and also to missing even previously located malignancies, and is difficult to guide to ensure examination of the entire cavity. Furthermore, fiber optic procedures are expensive: the average current cost for performing a fiber optic examination is about $1800.
In addition, much key information which may be gleaned from the thickness, homogeneity, and displacement of some internal tissue structures, as for example the endometrium, is unavailable through either biopsy or fiber optic procedures because neither blind biopsy needles nor fiber optic devices are capable of reliably determining internal strictural shapes or sizes, or of determining tissue thicknesses.
Moreover, many of the above-described treatments are in-patient procedures, involving hospital stays of at least one night, second and sometimes subsequent return visits, and often substantial discomfort to the patient. The treatments also frequently result in at least temporary or partial incapacitation of the recipient, including (in uterine examinations) the ability to engage in sexual intercourse.
Perhaps the most troubling difficulty with prior art procedures for the treatment of PMB, however, has been that they are conducted based on the assumption that there exists within the patient a malignancy to be found: it has in fact been found that most women who suffer from PMB bleed for other reasons. The performance of procedures like those discussed above, therefore, can result in needless discomfort, including possible injury or infection to the patient, and in substantial economic and material waste as well.
Progress has been made through the employment of ultrasonic or sonographic or fluorographic equipment. Sonographic equipment is capable of mapping interior surfaces of cavities and tissue structures without unduly invasive or incisive intrusion, and generally without the necessity of piercing or cutting the patient. Moreover, sonographic equipment can survey the thickness and echogenicity of tissue structures such as the endometrium. But none of the sonographic attempts made so far have provided safe, economic, efficient, or accurate means for examining and removing biopsy samples and malignancies from the interior of body cavities, and especially multichambered cavities such as the human vagina and uterus.
Devices are known which combine biopsy devices with ultrasonic probes. Such combinations are shown in U.S. Pat. No. 4,576,175 to Epstein; U.S. Pat. No. 5,076,279 to Arenson et al; U.S. Pat. No. 5,398,690 to Batten et al.; and 5,596,991 to Tanaka. The devices taught by these references, however, each comprise a biopsy device integrally (and in most cases rigidly, i.e. non-rotatably) attached to a sonographic transducer. In the cases of Epstein, Arenson, and Tanaka, the biopsy devices are immovably attached to the transducer heads, while Batten allows some rotation of the biopsy device. But such devices are not satisfactory for use within the often curved, typically restricted spaces of multi-chambered cavities such as the uterus and vagina. The sheer bulk of the equipment precludes its use in many restricted cavities. Moreover, such apparatus is frequently unsatisfactory for use inside the body because the needle and transducer cannot be independently manipulatedxe2x80x94either at all, or (as in the case of the Batten device) to any adequate extent: the biopsy device being fixed to the transducer head, the needle and head must be manipulated together. Thus for example if a sweep survey of a cavity were attempted with such devices the biopsy needle would have to be swept back and forth with the transducer head, resulting at least in restriction of the movement of the transducer head, with consequent loss in the quality of the sonic survey, and not improbably in injury to the patient. Another effect is that because the biopsy device is fixed to the transducer head, it is impossible to gain as wide a view of the interior of the examined cavity while guiding the biopsy device as is possible (as taught herein) with separate devices. It is impossible, for example, with fixed devices to back the transducer head away from the biopsy needle or the inner portions of the cavity(ies) in general so as to broaden the perspective seen via the transducer without withdrawing the biopsy device.
Nor do devices like those taught in Epstein and Arenson allow for removal of the biopsy needle (with or without sample), and replacement of the needle with another device such as a snare adapted for the removal of polyps, without requiring removal of the entire transducer head and the necessity of starting the entire procedure again. Thus flexibility in examination, biopsy, and excision using devices of the type disclosed in the cited specifications is extremely limited.
U.S. Pat. No. 5,383,465 to Lesny et al. discloses a high-frequency ultrasonic instrument, also rigidly fixed to a biopsy probe. In addition to the limitations suffered by the fixed devices described above, the Lesny device is incapable of performing a broad-perspective examination of an interior organ under any circumstances. The types of transducers disclosed in Lesny permit only a very small (on the order of 16 millimeters diameter) viewing area. Thus devices ofthe Lesny type are capable (especially when rigidly wedded to a biopsy device) of examining only a limited portion of a cavity, and must be guided into position by other means, such as a fluoroscope.
U.S. Pat. No. 5,651,364 to Yock discloses method and apparatus for intravascular ultrasonic imaging and atherectomy. The apparatus comprises an ultrasound transducer disposed within a catheter, with capacity for carrying an atherectomy device or other rotary cutter and a balloon for urging the atherectomy device toward an atheroma for removal. In addition to suffering the sanie limitations described above for the other prior-art devices, including the Lesney device, the Yock apparatus comprises no means for removing a biopsy sample; it is adapted only for the loosening of unwanted material within blood vessels into the blood stream and is entirely unsuited to the performance of examination, biopsies, and excision within cavities of the type contemplated herein. Also, placement of the device must be performed under fluoroscopic guidance rather than ultrasound. Fluoroscopy exposes the patient to radiation, and virtually necessitates that the procedure be performed in a fluoroscopy suite, whereas ultrasound machines are portable, and ultrasound guided procedures can be performed anywhere, including at a patient""s hospital bedside. Moreover, like the other references, the Yock device is needlessly complex and expensive, both to make and operate, for the purposes disclosed herein.
Thus there is a need for a procedure for examining the interior of multi-chambered or curved, restricted-access cavities within human and other bodies, and for guiding biopsy or excision equipment to the location of lesions or other undesirable tissues or growths within the cavities, and of conducting the excision and removal of biopsy samples or undesirable tissues or growths in a simple, cost effective, reliable, and accurate manner, at reduced risk to the patient and without unnecessary agitation or removal of tissuexe2x80x94particularly healthy tissue. It is especially desirable that such procedures be accomplished without the necessity of removing or exchanging equipment already in place and in contact with the cavity or body, and especially equipment which is in contact with the walls of the cavity itself. There is a further need for apparatus with which to accomplish these ends.
Accordingly, it is an object of the invention to provide a simple, cost effective, reliable, and accurate procedure for examining the interior of multi-chambered or curved, restricted-access cavities within human and other bodies, and for guiding biopsy or excision equipment to the location of lesions or other undesirable tissues or growths within the cavity, and of conducting the excision and removal of biopsy samples or undesirable tissues or growths in a simple, cost effective, reliable, and accurate manner, without the removal or agitation of healthy or otherwise desired tissue.
It is a further object of the invention to provide procedures which permit the realization of the foregoing objects without the necessity of removing, disturbing, or exchanging equipment, and especially guidance equipment positioned within the body, and particularly within the walls of the cavity itself, while the procedure is being conducted.
It is a further object of the invention to provide procedures to accomplish the foregoing with reduced risk and reduced or no requirements for hospital stays.
It is a further object of the invention to provide apparatus with which to accomplish those ends.
It is yet another object of the invention to meet any or all of the needs summarized above.
These and such other objects of the invention as will become evident from the disclosure below are met by the invention disclosed herein. The invention is method and apparatus for internal examination of human and other subjects employing specially-modified catheters and biopsy wires, in combination with sonographic transducers, to provide unprecedented accuracy, economy, and efficiency in internal examination, diagnosis, biopsy, and surgical removal of lesions, tumors, polyps, etc.
In one aspect the invention provides apparatus for use, in combination with sonographic or fluoroscopic transducers, in the examination of and performance of biopsies within externally communicating multi-chambered body cavities comprising communicating inner and outer chambers, or within the curved or restricted spaces of externally communicating single-chamber cavities. In general the apparatus comprises a substantially tubular catheter adapted for insertion within a cavity, or into a multi-chambered cavity at least as far as the outer chamber; and a any of a wide variety of biopsy devices adapted for disposition on or within the catheter, and for deeper insertion into the cavity, or for insertion into the inner chamber through the catheter. By such means, and upon sonographic or fluoroscopic examination of the cavity, or of the inner chamber, abnormalities within the cavity may be located and the biopsy device may be guided to an abnormality, and the biopsy device may be used to remove from the inner chamber a sample of the abnormality. In cases in which the apparatus is used to examine and/or treat a multi-chambered cavity, the apparatus generally further comprises a sonographic or fluoroscopic transducer for placement proximate the inner chamber, preferably within the outer chamber, for sonographic or fluoroscopic examination of the inner chamber.
A preferred catheter according to this aspect of the invention comprises a substantially tubular body having an interior, an anterior end, and a fluid infusion port; the interior of the catheter being adapted for the accommodation of a biopsy device comprising an excision device and for the passage of a fluid, such as for example an intraluminal fluid, admitted via the fluid infusion port and delivered to the cavity in order to facilitate sonographic examination of the cavity; the anterior end of the catheter being adapted for passage and accommodation of the biopsy device and for passage of a fluid; and the fluid infusion port adapted for accommodation of a fluid infusion means and for passage of a fluid to the interior of the substantially tubular body. Such embodiments optionally comprise posterior ends adapted for fluid tight passage and accommodation of the biopsy device. Preferred catheters further comprise an offset insertion tip, to facilitate manipulation and operation of the biopsy device within the cavity, especially in the inner recesses where curved cavity walls or restricted spaces are involved. They also comprise fenders adapted to support the catheter in a selected juxtaposition relative to the cavity. In particular, such embodiments comprise either a bumper adapted to support the catheter against a wall of the cavity and thereby to restrain the catheter from insertion beyond a desired depth within the cavity, or a balloon adapted to prevent contact between a side of the catheter and a wall of the cavity, or both. It has been found advantageous in many applications to provide not one but at least two coaxially-disposed catheters, one being located inside the other, with a biopsy device being disposed in the manner previously described within the inner catheter. Optionally, catheters useful in practicing the invention, and particularly inner catheters or sheaths in those embodiments of the invention comprising more than one catheter, comprise blades adapted for the engagement and removal of tissue (such as for example polyps or samples of lesions or other malignancies), either by aspiration or by retaining the sample, as in a cusp, while the catheter is withdrawn from the subject. Preferably, such blades are reverse bias blades.
Catheters suitable for use in accordance with the invention optionally further comprise one or more side ports, preferably located in the anterior end of the catheter at or near the tip, for manipulating biopsy and excision devices and for facilitating aspiration of tissue samples. Such catheters, whether or not they comprise side ports, are optionally curved to facilitate manipulation of biopsy or excision devices and aspiration or removal of tissue samples. Provision of curves in the anterior end of such catheters has the effect of offsetting the catheter""s tip from the longitudinal axis of the catheter, which improves access by the catheter and any deployed biopsy or excision devices around corners or folds of tissue, etc. Manipulation and maneuvering of catheters and appurtenant excision or biopsy devices is also improved in some cases by making at least a portion of the catheter, and most typically the anterior end of the catheter, flexible. Similar, tapering of the anterior end or of the tip of the catheter is beneficial in many circumstances.
The apparatus aspect of the invention further generally comprises a biopsy device which comprises a sample-engaging or-excision device adapted for the engagement and ultimately the removal of tissue from the cavity, the excision device being selected from the group comprising forceps, snares, baskets, cauterizing devices, graspers, brushes, suction aspiration devices, and reverse bias blades. In general, the catheter (or catheters) and biopsy device are adapted such that the device may be manipulated or operated within the cavity, or even changed for another device or instrument, without the necessity of moving or removing the catheter(s), or disturbing its location. Once the tissue has been engaged and separated from the cavity wall, it may be removed from the cavity by any satisfactory means, including aspiration or simple removal of the biopsy device through the catheter(s) in place within the cavity.
In another aspect the invention provides a procedure for the sonographic examination of multi-chambered body cavities comprising communicating inner and outer chambers, or within curved or restricted spaces of externally communicating single-chamber cavities, and for the removal of tissue or samples from such cavities. In general, the procedure aspect of the invention comprises the steps of inserting a substantially tubular catheter into the cavity, or at least as far as the outer chamber of a multi-chambered cavity; inserting an excision device deeper into the cavity, or into the inner chamber of a multi-chambered cavity, through the catheter; disposing a sonographic transducer within the cavity, or within the outer chamber in substantial proximity to the inner chamber, so as to permit sonographic examination of the inner chamber; and sonographically examining the cavity or inner chamber. In examinations of multi-chambered cavities, as for example the human uterus and/or vagina, the outer chamber will often comprise a wall proximate the inner chamber, for example between the inner and outer chambers. It is adjacent to or near this wall that the transducer is typically placed in order to facilitate sonographic examination of the inner chamber. To say that the transducer is in substantial proximity to the inner chamber is to say that it is closely enough located and suitably disposed to permit effective sonographic examination of the interior of the chamber. In cases in which lesions or other abnormalities are detected the procedure comprises the further steps of sonographically locating/identifying the abnormality(ies) within the cavity or inner chamber, guiding the biopsy device to the abnormality, and removing a sample of the abnormality by means of the excision device. This can include removing a biopsy samplc(s) by means of the forceps discussed above, or cutting and removing polyps with a snare, or with suction aspirator with either a cutting edge at its anterior end or a reverse bias blade. An optional further step comprises the determination of the thickness and/or coloration of the walls of the cavity by means of the sonographic equipment, in order to check the walls for malignant conditions. As is well known to those skilled in the operation of sonographic equipment or in the interpretation of sonographic data, coloration may in some instances be determined by variations in echogenicity in a tissue wall. Sonographic examinations in accordance with the invention may be facilitated by the infusion of intraluminal fluid into the cavity to facilitate sonographic examination of cavity, particularly via the catheter and via specially adapted catheters according to the invention. The infusion of such fluids improves transmission of sonographic waves and, especially where fluid-tight seals may be maintained, permits dilation or xe2x80x9cinflationxe2x80x9d of the cavity so that the cavity structure is more fully extended and more complete examination of the tissue behind its walls is possible. In many instances the procedure is further eased by opening the outer chamber with a speculum and holding it open while the catheter and transducer are emplaced.
It may be seen from the foregoing that the use of the apparatus discussed, and in particular the apparatus aspects of the invention, including the catheter and the biopsy device, contributes directly to the achievement of the objective of the method aspects of the invention.